Emulsion polymerization of water insoluble omega-(n-perfluoroalkanesulfonyl) aminoalkyl acrylates or methacrylates



United States Patent 3,403,122 EMULSION POLYMERIZATION OF WATER IN-SOLUBLE OMEGA (N PERFLUOROALKANE- SULFONYL) AMINOALKYL ACRYLATES 0RMETHACRYLATES Patsy O. Sherman, Bloomington, and Samuel Smith,Roseville, Minn., assignors to Minnesota Mining and ManufacturingCompany, St. Paul, Minn., a corporation of Delaware No Drawing.Continuation-impart of application Ser. No. 232,855, Oct. 24, 1962. Thisapplication Dec. 22, 1967, Ser. No. 692,680 The portion of the term ofthe patent subsequent to Nov. 6, 1979, has been disclaimed Claims. (Cl.26029.6)

ABSTRACT OF THE DISCLOSURE A process for the emulsion polymerization ofrelatively water-insoluble, high molecular weight monomers which arecapable of undergoing free radical addition polymerization is disclosed.The process is carried out in an aqueous medium containing from about 5percent to about 50 percent of a water-soluble organic solvent which issubstantially inert with respect to reaction with the monomer and withrespect to attack by free radicals present during the course of theprocess and which is capable of dissolving at least about one percentw./v. of the said water-insoluble monomer at 25 C.

Cross reference to related applications This application is acontinuation-in-part of U.S. application Ser. No. 232,855 filed Oct. 24,1962, which is itself a continuation-in-part of U.S. application Ser.No. 650,294 filed Apr. 3, 1957, now U.S. Patent 3,062,765.

Detailed description The process of emulsion-polymerization is of greatindustrial importance, being used in the large scale preparation of mostrubbery polymers and copolymers and of some non-rubbery polymers. Thelatexes which are thus produced are sometimes coagulated to recover thesolid polymers, but they can be and are often used directly, such as forexample in latex paints, adhesives, coatings for textiles and paper,etc.

Heretofore it has been the general practice to carry out polymerizationin water-oil types of emulsion with the aid of emulsifying agents and inthe presence of free radical initiators. Although some monomersemulsionpolymerize easily, others especially those of high molecularweights and consequent low water solubility, can be polymerized by thismethod only with difliculty and in poor yield. Thus, specializedprocesses have been resorted to for the group of substantiallywater-insoluble mono.- mers, e.g. the use of special emulsifiers, themaintenance of a high concentration of emulsifier to maintain latexstability and pre-emulsification of the monomer in the water withhigh-speed agitation, followed by slow and carefully regulated agitationduring polymerization to avoid monomer droplet growth. In anotherprocess for the preparation of aqueous dispersions of polymers, bulk,solution or suspension polymerized materials are dissolved in a largequantity of solvent, the solution is dispersed in water containing arelatively large quantity of 3,403,122 Patented Sept. 24, 1968emulsifier with high speed agitation and the solvent is removed.

A number of difliculties attend these specialized processes and tend toreduce their utility. They are ditlicult and expensive processes tocarry out. Their products often contain sufficient emulsifier to renderfilms coated from them water sensitive. The latexes thus preparedinvariably have large particle sizes; and this either renders themunstable on storage for even short periods, particularly with dilution,changes of temperature, changes of pH, etc. (i.e. with particles of5,000 A. diameter or larger), or renders them undesirable for coatingsbecause of graininess, lack of luster, or microscopic pinholes presentin films formed by drying such latexes. In spite of such difiiculties,these specialized processes have been fairly successful with a number ofmonomers of low watersolubility. With similar monomers which aresubstantially water-insoluble, however, they have been generallyunsuccessful and such monomers have heretofore had to be polymerized bybulk and solution techniques.

It is an object of this invention to provide an eflicient and practicalprocess for the emulsion-polymerization of certain relativelywater-insoluble, ethylenically unsaturated monomers. It is anotherobject of the invention to provide a process for emulsion-polymerizingcertain ethylenically unsaturated monomers having high molecular weight,which are capable of undergoing free radical addition polymerization, toproduce latexes which are comparable to normal latexes of monomers ofrelatively lowmolecular weight instability, particle size, freedom fromexcess emulsifier, and the like. Other objects of the invention will beapparent from the following disclosure.

In accordance with the above and other objects of the present inventionit has been found that the emulsionpolymerization of ethylenicallyunsaturated monomers capable of undergoing free radical additionpolymeriza tion which, because of their high molecular weight andwater-insolubility are difficult or impossible to emulsionpolymerize byconventional methods, can readily be accomplished by carrying out thepolymerization in an aqueous medium containing about 5% to about 50% ofan inert water-soluble organic solvent in which the monomer is at leastslightly soluble.

The process of the invention using a water-organic solvent emulsionmedium is employed with monomer systems capable of undergoing freeradical addition polymerization, of which at least one monomer issoluble in an amount less than one part by weight in a mixture of partsby weight of methanol and 25 parts by weight of water at 25 C. By theuse of the process, monomers which cannot be successfullyemulsion-polymerized using the processes heretofore known to the art canbe emulsionpolymerized in good yield to produce stable, useful latexes.Thus, the process of the invention produces unexpectedly useful resultswithin the area of its operation. These results are especiallyunpredictable in the case of the fluorocarbon-containing monomers, whichcould not be expected to act in any way comparable to the correspondinghydrocarbon analogues thereof.

A convenient method of determining whether a particular monomer issufliciently water-insoluble so that the emulsion-polymerization processof the invention using a water:organic medium is advantageously appliedthereto is the following: (1) a solution of one gram of the monomer in80 grams of absolute methanol is prepared, and '(2) a measured amount ofwater is cautiously added to this solution until an endpoint isindicated by the appearance of turbidity or phase separation. If themonomer cannot be completely dissolved in the methanol, or if turbidityor phase separation appear before 25 milliliters of water have beenadded, the present process can be advantageously employed forpolymerization. Typical examples of such monomers are: lauryl, tridecyl,tetradecyl, hexadecyl and octadecy-l acrylates, methacrylates and vinylethers; higher vinyl esters such as vinyl laurate, vinyl myristate,vinyl palmitate and vinyl stearate; higher 1,1-dihydroperfluoroalkylacrylates and methacrylates such as 1,1-dihydroperfluorooctylmethacrylate and 1,1- dihydroperfiuorodecyl acrylate; w-(N-alkyl,N-perfluoroalkane) aminoalkyl ac'ryl-ates and methacrylates; higherfiuorinated vinyl esters such as vinyl, N-ethyl, N-perfluorooctanesulfonyl glycinate; perfluoroalkanesulfonamidoalkyl acrylates such asB-(N-ethyl, N-perfluorohexanesulfonyl) aminoethyl acrylate,

fi-(N-ethyl, N-perfluorooctanesulfonyl) aminoethyl acrylate,

fi-(N-propyl, N-perfluorooctanesulfonyl) aminoethyl acrylate,

,B-(N-ethyl, N-perfluorooctanesulfonyl) aminoethyl methacry-late,

w-(N-ethyl, N-perfluorooctanesulfonyl) aminodecyl acrylate,

fl-(N-perfluorododecanesulfonyl) aminoethyl acrylate,

and

,B-(N-butyl, N-perfluorooctanesulfonyl) aminoethyl methacrylate, and thelike.

The preferred perfluoroalkanesulfonamidoalkyl acrylate monomers whichare suitable for use in the process of the invention conform to theformula:

wherein R, is a perfluoroalkyl group containing from 6 to 12 carbonatoms, R is hydrogen or an alkyl group containing from one to fourcarbon atoms, m is from 2 to 10 and R is hydrogen or methyl. The stablelatexes of the present invention prepared using these fluorocarbonmonomers (which can be referred to as w-(N-perfluorO- alkanesulfonyl)aminoalkyl acrylates and methacry lates) can be used to size textilefabrics. The resulting coated fabrics have useful oiland water-repellentproperties.

The inert solvent which is used in the process is a water-solubleorganic solvent which will not react with the monomer. Examples ofsolvents which are suitable for the practice of the invention are loweralkanols, such as methanol, and ethanol; water-soluble glycols, such asethylene glycol, propylene glycol; water-soluble ketones such as acetoneand methyl ethyl ketone; cyclic others, such as dioxane; cyclic aminessuch as pyridine; and the like. While it is necessary to determineempirically which specific solvent will produce optimum results with anyparticular monomer system, any solvent of the type described Willproduce useful results in the process of the invention.

A further distinguishing characteristic of the relatively high molecularweight monomers which are useful in the process of the invention, aswell as the organic solvents useful therein, is that the monomer must besoluble to the extent of at least about one gram of monomer in 100 ml.of the particular solvent which is to be added to its emulsion medium.This requirement may also be expressed as requiring the monomer to besoluble to the extent of at least about 1% w./v. in the organic solvent.

In the process of the invention, the selected inert, water-solubleorganic solvent is added to the aqueous medium in amount of about toabout 50% by weight of that of the water present. Below about 5%concentrations of the solvent, its effects are very slight, while atconcentrations over about 50% the formation of precoagulum (anundesirable precipitate of polymer) tends to become excessive, therebyreducing the overall conversion of monomer to latex. The maximumbenefits of the process are invariably realized when the solventemployed is present in concentration ranging from 10% to 40% of theamount of water, and this range is therefore preferred.

In carrying out the process, once the latex has been formed it is, ofcourse, independent of the organic solvent, which can be removed bysteam or vacuum distillation or other comparable techniques, and can bereplaced by Water without adversely affecting the properties of theemulsion. This may be done if the odor or the flammability of thesolvent is undesirable in the particular application to which the latexis put.

Having thus broadly described the process of the invention, there areappended several specific examples of its operation. These examples areto be understood as illustrative only and should not be construed asbeing limiting in any sense. Thus, for example, any other conventionalwater-soluble free radical initiator may be used in place of thepotassium persulfate used in the examples (e.g. ammonium persulfate,hydrogen peroxide, sodium perbenzoate, etc.) as well as ultravioletlight or ionizing radiation. Furthermore, promoters can be used ifdesired, such as sodium bisulfite, ferrocyanide salts, ferrous salts andamines, and the like. Other variations known in the art can be used inconjunction with the process of this invention since the advantageouspresence of the specific solvents which are employed does not interferewith the operation of the conventional means known to the art to beuseful in processes involving emulsion-polymerization, and the use ofsuch variation is contemplated to be within the scope of the invention.

The procedure used in each of the examples, and the amounts of theingredients employed, is as follows, except as otherwise specified: Asuitable vessel is charged, frozen in liquid air, evacuated to apressure of less than 0.01 mm. of mercury, thawed and refrozen,re-evacuated and finally sealed. The vessel is then agitated in a 50 C.water bath for 16 hours. The charge, except where otherwise specified,is parts by weight of monomer, 5 parts of emulsifier, /2 part potassiumpersulfate, and parts of medium.

Example 1 The emulsion polymerization of vinyl stearate, a typical longchain hydrocarbon monomer suitabl for use in the process of theinvention.

To determine suitability of vinyl stearate for advantageous use in theprocess, water was titrated at room temperature into a solution of onegram of vinyl stearate in eighty grams of absolute methanol until theappearance of turbidity which remained after thoroughly mixing thesolution. It was found that eight milliliters of water were required.From this it is seen that the emulsion polymerization of vinyl stearatewill be improved by the addition of a suitable organic solvent to theemulsion medium.

The procedure set forth above was used for polymerizing each batchcontaining the ingredients and amounts thereof specified. Both anionicand cationic emulsifiers were used. In this connection, anionic (e.g.sodium stearate, potassium oleate, sodium lauryl sulfate, etc.),cationic (e.g. dodecylamine hydrochloride, cetyl trimethyl ammoniumbromide, etc.) and nonionic (e.g. alkyl aryl polyether alcohols)emulsifiers can all be used in the practice of our invention in the samemanner as they are when a conventional aqueous medium is used.

The following table shows the results obtained when vinyl stearate wassubjected to emulsion polymerization under varying conditions, in mediacontaining various amounts of organic solvents coming within the scopeof the invention. An attempt to produce a latex in a medium containingwater only is included for purposes of comparison.

TABLE I Conversion Average Emulsifier Medium Amt. to Latex, LatexRemarks Percent particle Size, A.

Sodium stearate Water, 180 47 30, 000 Coagulated substantiallyimmediately on standing. Do Water, 135; Methanol, 45- 77 900 Stable,fluid latex. Do Water, 126; Acetone, 54... 96 600 Viscous, stable latex.Sodium stearate (3 part Water, 126; Acetone, 64--." 82 1, 000 Stable,fluid latex. Dodecylamine H01 Water, 144; Acetone, 36 80 1, 000 do.

Example 2 to the higher members of series of monomers, as compared withthe results using the lower members of the series. Twenty mllllhters ofWa er we e era d y a 80h!- The average particle size in each of thelatexes produced tion of one gram of lauryl methacrylate in eighty gramswas l th 900 A, of methanol at room temperature before turbidity was s li of one gram f 1 1-dih d -o -fl h 1. observed thus indicating thesuitab hty of thrsmonomer methacrylate and1,1-dihydroperfluorooctylmethacrylate for conve on to a latex 111 amedlllm contalnmg in eighty grams of absolute methanol tolerated theaddigame solvent according to the process of the invention. tion of and20 milliliters of water respectively at room Significant and unexpec edImp o emen s 11 th 6 temperature before turbidity or phase separation.It was version and quahty are shown In he emul ion po ymenthus shownthat there would be no improvement of quality ZatiOII 0f lallfylmethacl'ylate when all ol'ganlc Solvent or percent conversion in theemulsion polymerization of is added to the aqueous emulslon m dlumtheformer with the addition of an appropriate organic Likewise, sevenm1ll1l1ters of water were tolerated at solvent to the emulsion medium ofthe former, but that room temperature by octadecyl methacrylate 1n thetitrasuch improvements could be expected with the latter. tion test. Thesuccessful emulsion-polymerization of These indications are borne out bythe data set forth in octadecyl methacrylate (which will not readilyemulsion- Table III.

TABLE III Conversion Extent of 1) 1 of in) 1 of Monomer EmulsifierMedium Amt. to Latex, Precoagu- Emulsified Precoagu- Appearance percentlation, Polymer lation of Latex percent 1,1-d1hydroperfluorohexylDodecylamine hydro- Water, 180 99 0 1.10 Clear fluid latex.

methacrylate. chloride.

no. do Water, 135; Methanol, 100 0 0. 92 Do. 1,1-dihydroperfluorcoctylDodecylamine hydro- Water, 180 40 30 0.21 0. 77 Fluid latex clear;

methacrylate. chloride.

Do. do Water, 185; Methanol, 45- 100 0 0.70 Do. Do. Potassium salt 01aWater, 180 18 0 49 0.96 Do.

highly fluorinated carboxylic acid. Do. .do Water, 126; Acetone, 54..."0 1. 24 D0.

1 Inherent viscosity. 2 Both of these monomers are over 1% soluble inmethanol and infinitely miscible with acetone at room temperature.

polymerize by conventional methods) is shown with four Example 4dlfierent emulslfiers waterzacetone mean The data set forth in Table IVshow the effects of in- Table II shows the results obtained: creasing(up to an optimum value) the percentage of TABLE II Conversion AverageMonomer Emulsifier Medium Amt. to Latex, Latex Appearance (1,)

percent Particle o! Latex Size, A

Lauryl methacrylate 1..-"... Duponol ME 3 Water, 180 52 1, 730 Largeamount of pre. 93

coagulation. do 8 Water, 144; Acetone, 36. 92 1, Very small amount of 1.31

. preeoagulatlon. Octadecyl methacrylate Duponol ME Water, 144; Acetone,36..-.. 87 800 Somewhat viscous 0. 48

a ex. Dodecylamlne hydrochloride Water, 144; Acetone, 36 95 1, 000Stable, fluid latex.-- 0. 61 Sodium stearate- Water, 108; Acetone,72...- 59 Some precoagulation" 0. 39 o Water, 90; Acetone, 90 60 do 0,25Potassium salt 0 ethy Water, 108; Acetone, 72..- 78 Small amount or 0.36

lvll-perfluoro-octane sulfonyl precoagulation. g cine. .jio Water, 90;Acetone, 90 0 Total precoagulation l Inherent viscosity. 2 Laurylmethacrylate and octadecyl methacrylate are both more than 10% solublein acetone at room temperature. 3 Fou parts of emulsifier were used..Not determined.

Example 3 organic solvent in the medium in the process of emulsion- 7polymerization of octadecyl acrylate with a hydrocarbon In this exampleare illustrated higher mo ec l emulsifier and with a fluorocarbonemulsifier. Improveweights which can be obtained by using the presentprocess ments in the percentage conversion of monomer to latex, as shownby the increased inherent viscosity of the prodmolecular weight of latex(as shown by the inherent visucts, and also the sharp line ofdemarcation which discosity), latex particle size and latex stabilityare shown to tinguishes the scope of operation of the process as applied75 be brought about by the addition of the solvent.

TABLE IV Conversion (1;) of Average Monomer Emulslfier Medium Amt. toLatex, Emulsified Latex Appearance of Latex Percent Polymer ParticleSize, A.

Octadecyl acrylate 2 Sodium stearate--.. Water, 180 49 0.32 10,000Unstable, coagulated almost immediately.

Do. do Water, 171; Acetone, 9 54 0.29 10,000 Do.

Do do. Water, 162; Acetone, 18 65 0.28 800 Viscous, stable.

Do! do. Water, 153; Acetone, 27 89 0. 34 600 Viscous, stable latex.

Do do- Water, 135; Acetone, 45 96 0. 61 600 Do.

Do. do Water, 126; Acetone, 54... 100 0.62 600 Do.

Do. Potassium salt of Water, 180 Complete prec0ag N-ethyl, N-perulation.fiuorooctane sulfonyl glycine.

Do. .do Water, 153; Acetone, 27..." 62 0.32 1,000 Stable, fluid latex.

Do. do Water, 126; Acetone, 54..." 97 0. 48 1,000 Do.

1 Inherent viscosity.

Example The results (both in quality and in percent conversion 2 ofmonomer to latex polymer) of carrying out the emulsion-polymerization ofseveral fluorocarbon monomers in aqueous solutions of organic solventsare illustrated in the following table. In some cases control lots 2Octadecyl acrylate is about 1% soluble in methanol and more than solublein acetone at room temperature.

procedure was that described just prior to Example 1. The resultinglatex represented 90% conversion to stably emulsified product. It wascoagulated to form a soft, flexible plastic.

Example 7 Emulsion-copolymerization of chloroprene and ,B-(N- (in whichthe polymerizations are carried out in water) propyl,N-perfluorooctanesulionyl)-aminoethyl acrylate.

are included for comparison.

Chloroprene (5 grams) and ,B-(N-propyl, N-perfiuoro TABLE V ConversionAverage Monomer Emulsitier Medium Amt. to Latex, Latex AppearancePercent Particle of Latex Size, A.

1,l-dihydroperfiuoro-hexylacrylate Dogfcyllamine hydro- Water, 180 97900 Clear stable.

c on e. Do "do Water, 144; Acetone, 36 100 900 Do. 1,1,-dihydroperflu0r0-decylacrylate Potassium salt of a highly Water, 180 0 Total,precoagulaflutrinated carboxylic tion. aci Do do Water, 135; Methanol,88 000 Clear stable. B-(N-ethyl, N-perfiuorohexane sul- Potassium saltof N-ethyl, Water, 180 27 Couldy, unstable, ionyl)- aminoethyl acrylate.N-perfiuoro-octane snllarge amount of fonyl glycine. precoagulation. Dodo Water, 126; Acetone, 54 99 Clear, stable. e-(N-ethyl,N-perfluoro-octane sul- .do Water, 180 0 Totalprecoagulafonyl)-aminoethyl acrylate. tion.

Do .do Water, 126; Acetone, 54 100 900 Cloudy, stable.

Do Potassium salt of a highly Water, 180 24 5,000 Cloudy, almost totalfluolrinated carboxylic precoagulation. aci

Do Same (10 parts) d0 100 200,000 Cloudy, viscous, unstable, coagulatedsubstantially immediately.

Do do Water, 108; Methanol, 72 94 Slighglly cloudy,

sta e.

Do do Water, 126; Acetone, 54 93 900 Cloudy, stable.

B-(N-propyl, N-perfluoro-octane sul- Potassium salt of N'per- Water,108; Acetone, 72 95 Do.

fon D-aminoethyI acrylate. filuoro-octane sulionyl g ycine. fl-(N-ethyl,N-perfiuoro-octane sul- Potassium salt of N-ethyl, Water, 180 0 Totalprecoagula- Ionyl) -aminoethyl methacrylate. N -perflu0ro-octanesultion.

fonyl glycine. Do ..do Water, 126; Acetone, 54 96 About 1,000... Clearstable latex. Do N,N-dimethyl-('y-perflu0ro- Water, 126; Acetic acid,54... 93 do Do.

octane sulIonyl-amido)- propyl amine hydrochloride. w-(N-ethyl,N-perfluorooctane sul- Potassium salt of N-ethyl, Water, 126; Acetone,54 89 -do Do.

!onyl)-aminodecyl acrylate. N-perfluoro-octane sulfonyl glycine.octadecyl acrylate: 50 B-(N-pro- N,N-dimethyl-('y-perfiuor0- ....do 82.do Do.

octane sulfonyl-amido)- propyl amine hydrochloride.

pyl, N -perfluoro-octane sulfonyl)- amlnoethyl acrylate.

Example 6 B-(N-propyl, N -perfluorooctanesulfonyl)-aminoethyl acrylate,of the formula:

CaF SO 2N (C3H7) was emulsion homopolyrnerized as follows: About 12.6grams of water, 0.5 gram of emulsifier, 10 grams of monomer, 5.4 gramsof acetone and 0.02 gram of potassium persulfate were charged tooctanesulfonyl)-arninoethyl acrylate (5 grams) were polymerized in aheavy-Walled Pyrex glass amponle in the presence of 12.6 grams of water,0.5 gram of a heavy-walled Pyrex glass ampoule. The polymerizationrubber.

3,403,122 9 10 Example 8 tion in which both comonomers are normallydifiicultly Emulsion-copolymerization of chloroprene and B-(N- efnulsimpolymefizable. Permanent internal plastifiiza' ethyl,N-perfluorooctanesulfonyl) aminoethyl methacrybe achleved Such Polymers.the relatively water-insoluble long-chain monomer acting as theplaslate.

A 250 milliliter 3-neck flask fitted with a stirrer and 5 Heller Thls.piastlclzer System has i afivantages over regular plastlcizer systemsof not mlgratmg and of not equlpmem for pufgmg wlth Oxygen-free mtmgenwas being diflicult to mix homogeneously with the polymer charged asfollows.

as are regular plastlcizers used in latex formulations. As

Grams chloroprene 25 In other plast cizers the long-chain comonomeroften Distilled water 63 makes it possible to form films at roomtemperature Acetone L: 27 from the emulsion state. Unplasticizedpolyvmyl acetate, ZE 'N fi f (emulsifier) 2.5 for example, applied to asurface from an emulsion and K S O 01 dried at room temperature does notform a continuous 2 2 8 film. In order to form a continuous film, itmust be heated After 2 hou s reac t 5 C- llnder an atmosphere to atleast 35 C. and this makes it impractical for some of nitrogen 86% ofthe chloroprene was converted to appfieatiens l t i t A l i f n stablyemulsified polymer. 25 grams of fi-(N-ethyl, N- 85%;15% copolymer byweight of vinyl acetate and pel'flllol'ooctaflesulfonyl) amifloethylmethacfylflte were vinyl stearate, however, does form a continuous filmat then added to the flask and the reaction continued for roomtemperature upon drying, 4.5 hOUIS at which time 83% Of the total111011011161 was Emulsion copolymers of onenormally-difficult-toconverted to stable copolymer latex.emulsion-polymerize fluorocarbon monomer and a hydrocarbon monomer arehighly useful as cloth treat- Example 9 ments to impart oleophobic andhydrophobic properties to the treated cloth. A preferred class ofcopolymers of this type are copolymers of theperfluoroalkanesulfonamidoalkyl acrylates, with normally easily emulsionpolymerizable monomers such as ethylene, vinyl acetate, vinyl chloride,vinyl fluoride, vinylidene chlo- Emulsion-copolymerization of vinylchloride and vinyl stearate.

Vinyl chloride is sufliciently water-soluble to emulsionhomopolymerizeeasily in water alone as a medium, whilst vinyl stearate is suflicientlywater-insoluble so that its emulsion-homopolymerization is extremelydifficult by heretofore known methods.

The following were charged to each of two crown cap pressure bottles:

trile, vinylidene cyanide, styrene, alkylated styrenes, sulfonatedstyrenes, halogenated styrenes, acrylic acid and alkyl esters thereof,methacrylic acid and alkyl esters Pm thereof, methacrylonitrile,acrylamide, methacrylamide, Vinyl id 50 vinyl carbazole, vinylpyrrolidone, vinyl pyridine, vinyl Vinyl Stearate 5 alkyl ethers, vinylalkyl ketones, butadiene, chloroprene, Sodium Stearate 4 fluoroprene andisoprene. potassium lf t 5 It will thus be seen that the process of theinvention Water and acetone as shown i the table Set f th produceshighly advantageous and desirable results.

below A useful procedure utilizing the novel features of the inventionand suitable for production of large amounts Excess Vmyl chlonde addedas h last f' of useful latexes is illustrated by the following example.and the excess was permitted to volatile, thus purging the bottles ofair prior to sealing. The bottles were Example 10 tumbled end-over-endin a C. bath until about 30% A 75 gallon glass-lined kettle equippedwith a paddle conversion to polymer was obtained. The polymer wasstirrer and means for heating was charged with the folthen separated,washed with water and finally extracted 45 lowing ingredients: withboiling methanol in a soxhlet apparatus to remove Lb. all unreactedvinyl stearate. Chlorine contents were then Deionized Water 126determined on the dry polymer. The results are shown Potassium salt ofN-ethyl, N-perfluorooctanesulbelow. fonyl glycine 5 Percent Polymer RunNo. Emulsion Medium Appearance of Latex C1 in Composition Polymer 1Water, 180 Completely precoagulated--. 49.0 86:14 VigJhViSt 2 Water,126; Acetone, 54-.-" Stable, fluid 1am 36.5 64135 r io'iEvist (by wt.).

The last three examples demonstrate the important results obtained withthe process of the invention in p-(N-propyl, N-perfluorooctanesulfonyl)aminoethyl copolymerization reactions involving at least one long 100acrylate chain, highly water insoluble monomer, in producing Acetolie 154 uperior latexes and increasing the rate of combination of PotasslumPersu fate the long chain monomer with smaller, more water-soluble Thewater was placed in the kettle first and was boiled comonomers. to expeldissolved air. The emulsifier was then dissolved These and similaremulsion copolymers of (1) in the hot water while stirring under ablanket of nitrm ethylenically unsaturated monomers which normally gen.The acetone and the monomer were separately undergo free radicaladdition polymerization with ease mixed and the mixture was added. Thetemperature was (i.e. which are soluble in an amount greater than aboutthen adjusted to 50 C. and the potassium persulfate was one part byweight in a mixture of 80 parts by weight added. The contents of thekettle were then stirred. of methanol and 25 parts by weight of water at25 C.) Nitrogen pressure of 18 p.s.i. was maintained in the ketand (2)the normally difiicultly emulsion polymerizable tle throughout theperiod of reaction. After about two monomers as described herein haveinteresting and hours at 50 C., polymerization was essentially complete,

unusual utility as do copolymers according to the invenbut stirring atthis temperature was continued for an ride, vinylidene fluoride, vinylchloroacetate, acryloni-- additional two hour period. A completeconversion to polymer was obtained, of which 90% was present in stablelatex form. The average latex particle diameter, measured by lightscattering techniques, was of the order of 1000 A. The polymer hadinherent viscosity=0.4l.

As used herein, the term inherent viscosity signifies the numberobtained by dividing the natural logarithm of the relative viscosity bythe concentration of the polymer in grams per 100 ml. of the solvent inwhich viscosity is determined. The relative viscosity is the ratio ofsolution viscosity to solvent viscosity. In the case of hydrocarbonpolymers, inherent viscosity was determined using 0.15% solution in 4:1benzenezisopropanol mixtures; in the case of fluorocarbon polymers,inherent viscosity was determined using 0.15% solutions in 2:1 methylperfluorobutyratezacetone mixtures. All determinations were made at 25C.

The useful latexes of the present invention as hereinabove described arefurther characterized by the fact that they are stable latexes havingparticle sizes of the order of 1000 A. (i.e., in the range of about 700to about 1500 A.), comprised of polymers made from significant amountsof monomers of relatively high molecular weight.

What is claimed is:

1. The process for emulsion polymerization which comprises charging to asuitable reaction vessel a monomer charge which includes awater-insoluble, highmolecular weight w-(N-perfluoroalkanesulfonyl)aminoalkyl ester monomer selected from the class consisting of acrylatesand methacrylates wherein the nitrogen atom is substituted by a memberof the class consisting of hydrogen and alkyl groups containing from oneto four carbon atoms, said monomer being soluble in an amount less thanabout one part by Weight in a mixture of 80 parts by weight of methanoland 25 parts by weight of water at 25 C., an aqueous medium containingfrom about 5 percent to about 50 percent of a water-soluble organicsolvent which is substantially inert with respect to reaction with themonomer and with respect to attack by free radicals present during thecourse of the process and which is capable of dissolving at least aboutone percent w./v. of the said water-insoluble monomer at 25 C., and anemulsifier, and agitating the resulting charge under free radicalconditions until appreciable polymerization has occurred.

2. The process of claim 1 wherein the monomer charge includesB-(N-ethyl, N-perfluorooctanesulfonyl) aminoethyl methacrylate.

3. The process of claim 1 wherein the monomer charge includesw-(N-ethyl, N-perfiuorooctanesulfonyl) aminodecyl acrylate.

4. The process of claim 1 wherein the monomer charge includes anethylenically unsaturated free radical addition polymerizable monomerwhich is soluble in an amount greater than about one part by weight in amixture of parts by Weight of methanol and 25 parts by weight of waterat 25 C.

5. The process of claim 4 wherein the monomer charge consists ofchloroprene and fl-(Nethyl, N-perfluorooctanesulfonyl) aminoethylmethacrylate.

6. A stable latex of particle size of the order of about 1000 A.produced by charging to a suitable reaction vessel a monomer chargewhich includes a water-insoluble, high-molecular weightw-(N-perfluoroalkanesulfonyl) aminoalkyl ester monomer selected from theclass consisting of acrylates and methacrylates wherein the nitrogenatom is substituted by a member of the class consisting of hydrogen andalkyl groups containing from one to four carbon atoms, said monomerbeing soluble in an amount less than about one part by weight in amixture of 80 parts by weight of methanol and 25 parts by weight ofwater at 25 C., an aqueous medium containing from about 5 percent toabout 50 percent of a water-soluble organic solvent which issubstantially inert with respect to reaction with the monomer and withrespect to attack by free radicals present during the course of theprocess and which is capable of dissolving at least about one percentw./v. of the said water-insoluble monomer at 25 C., and an emulsifier,and agitating the resulting charge under the free radical conditionsuntil the latex has formed.

7. A latex according to claim 6 wherein the monomer charge includesB-(N-ethyl, N-perfiuorooctanesulfonyl) aminoethyl methacrylate.

8. A latex according to claim 6 wherein the monomer charge includesw-(N-ethyl, N-perfluorooctanesulfonyl) aminodecyl acrylate.

9. A latex according to claim 6 wherein the monomer charge includes anethylenically unsaturated free radical addition polymerizable monomerwhich is soluble in an amount greater than about one part by weight in amixture of 80 parts by weight of methanol and 25 parts by weight ofwater at 25 C.

10. A latex according to claim 9 wherein the monomer charge consists ofchloroprene and B-(N-ethyl, N-perfluorooctanesulfonyl) aminoethylmethacrylate.

References Cited UNITED STATES PATENTS 3,062,765 11/1962 Sherman et a1.26029.6

MURRAY TILLMAN, Primary Examiner.

W. I. BRIGGS, SR., Assistant Examiner.

